Cochlear otospongiosis etiology, diagnosis and therapeutic implications.

First, the authors discuss the most valuable way to correlate specific morphological changes encountered in cochlear otospongiosis with sensorineural hearing loss. They think that biochemical factors may be responsible for this association of cochlear otospongiosis and histopathologic changes, and they explain their enzymatic concept resulting from experimental findings and cyto-clinical relationship. Second, the authors analyze clinical, audiometric and X-Rays investigations enabling the diagnosis of cochlear otospongiosis, in its pure pereceptive form as well as in the perceptive component added to the conductive loss in far-advanced mixed audiometric types in surgical otospongiosis. They present two typical cases of cochlear otospongiosis: one combines clinical history, audiometric test and post mortem investigations;-the other shows the passage from a pure cochlear otospongiosis to a secondary stapedial fixation, ten years later, thus confirming by audiometric data and by stapedectomy the otospongiotic etiology of this previous pure sensorineural loss. Finally, they insist upon the great interest of establishing an early diagnosis in cochlear otospongiosis on account of its therapeutic implication, particularly from the enzymatic point of view.